Busbar rating

[andrew.tkelly]

Hi,

Someone asked me this question the other day, and I wasn't quite sure how to answer it: If a panel says it is rated for 125A, is it just talking about the busbar portion of the panel? Or is it talking about the whole structural framework of the panel?

Regards,
Andy

 

[electrofelon]

Hi,

Someone asked me this question the other day, and I wasn't quite sure how to answer it: If a panel says it is rated for 125A, is it just talking about the busbar portion of the panel? Or is it talking about the whole structural framework of the panel?

Regards,
Andy

I would say if it's a MLO panel, than it is the rating of the busbar. If it's a main breaker panel, that would be the rating of the main breaker, and the bus bar would be equal to or higher than that (usually the same). I'm sure there UL/ manufacturing standards for space for the cabinet that the panelboard is mounted in for a given amperage.

 

[ggunn]

Hi,

Someone asked me this question the other day, and I wasn't quite sure how to answer it: If a panel says it is rated for 125A, is it just talking about the busbar portion of the panel? Or is it talking about the whole structural framework of the panel?

Regards,
Andy

It depends on the manufacturer. Some have separate stickers for the enclosure rating and for the "guts" of the panel rating, and sometimes they are different. You have to be careful; sometimes the enclosure sticker will say 225A but the bus is only 200A.